CARDIAC MAGNETIC RESONANCE IMAGING OF PATENT DUCTUS ARTERIOSUS IN THREE DOGS

Patent ductus arteriosus (PDA) is the most common congenital cardiovascular disorder in dogs and requires an accurate diagnosis for an appropriate treatment. Cardiac MRI (cMRI) has been reported as a method for characterization of canine thoracic vasculature. However, to the authors’ knowledge, no published studies describe evaluation of canine PDA through cMRI. Three dogs were selected for this exploratory study. Electrocardiogram gating and breath‐hold techniques were performed using a 3T MR scanner. Both black blood imaging and bright blood cine acquisitions were performed. Quantification of stroke volume (SV) and shunting volume were calculated using a stack of short‐axis cine images. Additional 4D (three‐spatial dimensions plus time)‐TRAK (time‐resolved MR angiography with keyhole) sequences were conducted in patient 2 to verify other vasculature abnormality. Black blood images clearly depicted the course of the ductus from the descending aorta to the pulmonary artery in all three dogs. Morphological evaluation of PDA classified patients 1 and 2 as Type 2a and patient 3 as Type 1. Patient 2 was confirmed to have a concurrent persistent left cranial vena cava. Left ventricular SV, right ventricular SV, and left‐to‐right SV ratio were 12.4 ml, 3.36 ml, and 3.704, respectively, in patient 1; 6.85 ml, 1.22 ml, and 5.60 in the patient 2; and 3.67 ml, 2.14 ml, and 1.702 in patient 3. Findings indicated that cMRI is a feasible method for characterizing the morphology of PDA and extracardiac vasculature anomalies in dogs.     

天然产物中齐墩果酸和熊果酸提取和分析方法研究进展

对不同天然产物中熊果酸和齐墩果酸的提取纯化方法及分析方法进行综述,并比较了各方法的优缺点。     

氮肥后移对绿洲灌区玉米干物质积累和产量构成的调控效应

【目的】针对绿洲灌区传统施氮技术下,全膜覆盖玉米生育后期土壤氮肥供应不足、早衰和减产等问题,探讨氮肥后移对玉米干物质积累和产量构成的影响,以期为优化试区氮肥管理提供理论依据。【方法】2012—2015年,于河西绿洲灌区进行大田试验,在总施氮量相同且基肥和大喇叭口期追肥分别占总施氮量20%和40%条件下,设3个施氮处理:氮肥后移20%(拔节肥10%+花粒肥30%,M1)、氮肥后移10%(拔节肥20%+花粒肥20%,M2)和传统施氮(拔节肥30%+花粒肥10%,M3),研究不同氮肥追施制度对玉米干物质积累动态和产量构成的调控效应。【结果】氮肥后移增大了玉米干物质最大增长速率和干物质平均增长速率,提前了干物质最大增长速度出现的天数。在氮肥后移20%施氮制度下,玉米干物质最大增长速率和干物质平均增长速率分别较传统施氮处理提高15.6%和6.6%,玉米干物质最大增长速率出现的天数较传统施氮提前2.9 d。施氮制度对玉米生物产量、籽粒产量、收获指数、有效穗数、穗粒数和千粒重均有显著影响。氮肥后移20%施氮制度下,玉米生物产量较传统施氮处理高6.6%,但氮肥后移10%处理生物产量与传统施氮处理差异不显著;氮肥后移20%和10%处理玉米的籽粒产量分别较传统施氮处理提高14.1%和5.1%;氮肥后移20%施氮处理收获指数较传统施氮处理高7.5%,但氮肥后移10%施氮处理与传统施氮处理差异不显著;氮肥后移20%施氮处理下,玉米有效穗数、穗粒数和千粒重分别较传统施氮处理高8.9%、12.9%、5.8%,但氮肥后移10%处理的千粒重与传统施氮处理差异不显著。通径分析表明,氮肥后移主要通过提高有效穗数,进一步提高穗粒数和千粒重,从而提高产量。说明氮肥后移20%施氮处理通过优化玉米有效穗数、穗粒数和千粒重对产量产生了调控作用。【结论】在河西绿洲灌区,总施氮量450 kg·hm~(-2)时,玉米拔节期追肥45 kg·hm~(-2)、大喇叭口期追肥180 kg·hm~(-2)、花后10 d追肥135 kg·hm~(-2)为该区获得玉米高产的理想施氮制度。     

Establishment and Application of Loop-mediated Isothermal Amplification for Rapid Detection of Porcine Epidemic Diarrhea Virus

This study was aimed to establish a loop-mediated isothermal amplification (LAMP) assay for detection of porcine epidemic diarrhea virus (PEDV), and provide a simple, sensitive, accurate and reliable tool for diagnosis of PEDV.The conservative PEDV N gene (GenBank accession number: KT799997) of PEDV was selected as a target to design six specific primers.The reaction system and temperature of LAMP were optimized, and the LAMP method for specific amplification of PEDV was established. Results showed that the PEDV LAMP detection method was established successfully, and it could detect PEDV specifically at 60℃ for 60 min,and the detection limit was 91 copies/μL, which was one hundred-fold higher than conventional RT-PCR method.75 clinical samples were detected by LAMP and PCR, respectively, the coincidence of LAMP and PCR was about 97.3%. All the data suggested that the LAMP assay had strong specificity, high sensitivity, simple operation, low equipment requirement, and was suitable for rapid detection of PEDV clinical samples.     

应用CNCPS方法和体外产气法研究豆腐渣饲料的营养价值

为揭示豆腐渣对反刍动物的饲用价值,本试验采用康奈尔净碳水化合物-蛋白质体系（CNCPS）和体外产气法对豆腐渣营养价值进行评定。测定豆腐渣的CNCPS营养成分与体外发酵参数,应用CNCPS公式计算碳水化合物（CHO）和粗蛋白质（CP）中各组分含量。结果显示,豆腐渣的CP含量为14%~25%,粗脂肪（EE）含量为1.9%~2.9%,代谢能（ME）为10~12 MJ/kg DM;易在瘤胃中降解的蛋白质（PA＋PB₁）和在瘤胃中缓慢降解的粗蛋白质（PB₂＋PB₃）的含量相当,不可降解真蛋白质（PC）含量较少;潜在可利用碳水化合物（CA＋CB₁＋CB₂）较高;体外发酵产气量均达到70 mL,氨态氮（NH₃-N）浓度在8~23 mg/dL,总挥发性脂肪酸（TVFA）在46~70 mmol/L。而不同来源的豆腐渣营养成分和发酵情况存在显著差异,且CNCPS碳水化合物、蛋白质组分的优劣不同。凌源豆腐渣的最大产气量（B）最高,极显著高于其他3种苹果渣（P＜0.01）,而各豆腐渣的产气速度（C）无显著差异（P＞0.05）。辽源豆腐渣氨态氮（NH₃-N）含量最高,极显著高于其他饲料（P＜0.01）。不同地方豆腐渣瘤胃液挥发性脂肪酸比例差异极显著（P＜0.01）。不同来源的豆腐渣的总可消化养分（TDN）及其他能值差异较大,以新民豆腐渣的能值最低,极显著低于其他苹果渣（P＜0.01）。综上可知,作为反刍动物非粮饲料,豆腐渣为反刍动物提供的可利用能值高,利于瘤胃微生物蛋白质合成。     

The Epidemiology and Characteristics of Q fever and Co‐infections with Scrub Typhus,Murine Typhus or Leptospirosis in Taiwan: A Nationwide Database Study

Q fever (QF) is a worldwide zoonosis associated with outbreaks. Only a few nationwide studies regarding the surveillance and epidemiology of human QF have been reported. Although QF is endemic in Taiwan, a nationwide database investigation of the epidemiology and characteristics of QF and its associations with scrub typhus (ST), murine typhus (MT) and leptospirosis (LS) has never been reported. We analysed nationwide databases of suspected QF, ST, MT and LS cases from October 2007 to December 2014 obtained from the Centers for Disease Control, Taiwan. A total of 468 (4.2%) QF cases were identified among 11 109 suspected QF cases. QF cases were mainly distributed in the southern and Kaohsiung–Pingtung regions but rarely in the eastern region. Compared to non‐QF cases, QF cases had significantly higher percentages of males (88.7 versus 66.2%) and high‐risk occupations (farming, animal husbandry or veterinary medicine) (16.2 versus 10.5%). But the percentages of specific animal contact, including cattle (0.6 versus 0.8%) and goats (0.9 versus 1.0%), were low in both. The majority of suspected QF cases (89.4%) were simultaneously suspected with ST, MT or LS, and the combinations of suspected diseases differed between regions. The number of suspected QF cases from the eastern region decreased since 2009, which was not observed in other regions. A total of 1420 (12.8%) cases had confirmed diseases, including QF (453, 4.1%), QF+ST (7, 0.06%), QF+MT (4, 0.04%), QF+LS (4, 0.04%), MT (186, 1.7%), ST (545, 4.9%), ST+LS (11, 0.1%) and LS (210, 1.9%). Compared to cases of unknown disease, QF cases had larger percentages of high‐risk occupations (16.2 versus 9.6%) but similar histories of animal contact (29.8 versus 25.1%). QF is an endemic disease in southern Taiwan. It is difficult to differentiate QF from ST, MT or LS only by high‐risk occupations and history of animal contact, and co‐infection of QF with these diseases should be considered.     

我国青藏高原地区牦牛草地放牧系统管理及优化

基于牦牛所处地理环境,即青藏高原的特殊性,以及牦牛放牧这一生产方式在该地区第一产业中的重要地位,国内外学者从牦牛放牧系统的管理出发,对该系统中各因子之间的相互响应进行了研究,主要包括当放牧制度不同时,系统中的初级生产力和次级生产力的表现特征。从不同放牧制度中草地和家畜的特征表现,再到人为管理对这两种生产力的影响,研究者通过对比和试验进行了系统优化方法的探索。笔者通过对现阶段已有的研究成果进行整理和分析,概括在不同的放牧管理方式下草地放牧系统中的牦牛在生产力水平方面的差异,以及草地对不同放牧强度的响应,探究青藏高原地区牦牛放牧方式如何影响草畜之间的互作关系。在此基础上,分析其在实际生产活动中存在的问题,以及如何通过改进管理制度优化生产的办法,并对牦牛放牧系统发展进行了展望。     

污泥对草坪草逆境生理的影响

日益增长的污水处理副产物——污泥的处置问题越来越引起人们的关注,将污泥应用于草坪草的种植被认为是污泥资源化利用的可行途径之一。本文综述了污泥对草坪草逆境生理影响的研究进展,众多研究表明,适宜用量的污泥对草坪草叶绿素及光合效应、矿质营养、渗透调节物质和抗氧化酶系统均有有益影响,能提高其应对逆境的适应能力;过量施用污泥则会影响草坪草的生长,不同的草种对污泥施用量的要求不同。污泥能提高草坪草抗逆性的原因可能是由于污泥富含多种营养元素和生物活性物质,但其提高草坪草抗逆性的内在机制还有待进一步研究。